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Canadian Contribution to MAP D-PHASE

R. McTaggart-Cowan, M. Desgagne, J. Cote, S. Gravel, C. Girard, A. Erfani, J. Milbrandt, C. Jones University of Quebec at Montreal (UQAM) / Environment Canada, Quebec, Canada. Canadian Contribution to MAP D-PHASE. Outline. Canadian motivation and support

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Canadian Contribution to MAP D-PHASE

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  1. R. McTaggart-Cowan, M. Desgagne, J. Cote, S. Gravel, C. Girard, A. Erfani, J. Milbrandt, C. Jones University of Quebec at Montreal (UQAM) / Environment Canada, Quebec, Canada Canadian Contribution to MAP D-PHASE

  2. Outline • Canadian motivation and support • Description of the GEM modelling system • Multiscale comparison of events in the MAP and Vancouver 2010 regions • Dynamical and physical representation of heavy precipitation episodes in the model • Opportunity for “proof of concept” and verification

  3. Proposed Support Canadian operational / on-demand support for MAP D-PHASE

  4. Motivation for Involvement • Regional experience from the original MAP project • Identified problems by “stressing” the system • Motivated improvements to model formulation • Proof of concept for high resolution short-term forecasting in mountains – valuable for Vancouver Olympics 2010 project • Venues are particularly sensitive to precip amount and species

  5. Model Description • Global Environmental Multiscale (GEM) model has been developed extensively since the MC2 was used in MAP • GEM runs in global (uniform/variable reso) + LAM configuration – unified model structure • Non-hydrostatic primitive equations solved using an Implicit SL scheme Operational GEM Regional stretched Configuration

  6. Model Description • Self-nesting allows for a consistent use of physical parameterizations: • Kong and Yau microphysics (2 liq, 2 ice) – upgrade to Milbrandt and Yau is possible • TKE boundary layer closure • Kain-Fritsch convection (10 km MAP-Regional domain only) • This allows nesting of hydrometeor species – important to reduce spin-up

  7. Predictability: Large Scale • Synoptic scale patterns modulate the internal structure of the systems – they must be well-represented Vancouver snow (35cm Cyprus) enhanced IR image 0600 UTC 8 March 2006 MAP IOP-2 Cyclone enhanced IR image 1200 UTC 20 September 1999

  8. Predictability: Large Scale • Despite satellite DA, useful predictability can be <6h on West Coast • Ensemble techniques may be an approach x Observation increment of radiosonde temperatures for 16 June 2006 Observation increment from AMSU-A brightness temperatures 14 Feb 2006

  9. Regional Modelling • Use of an intermediate domain (10km) will promote development of mesoscale signal and permit hydrometeor nesting

  10. High Resolution Modelling • During MAP, MC2 ran with smoothed (approximately x5) orography – GEM will run with full resolution field

  11. Model Dynamics High Resolution Modelling Vertical motion fields from the GEM for a cosine idealized mountain case (C~.5) • MAP revealed problems with the MC2 • New vertical coordinate (Schar) developed • Numerical inconsistency eliminated • Reduction of GEM waves is a priority GEM with standard background GEM with modified background

  12. Model Microphysics High Resolution Modelling • Advanced microphysics scheme is being developed for GEM – 3 moment bulk with 2 liquid, 4 ice phases (Milbrandt and Yau) Multimoment bulk estimate of DSD • Accurate DSD shape prediction important for fall speed estim-ates and conversion rate calculations Observed 1 Moment Bulk 3 Moment Bulk 101 100 N(D) 10-1 10-2 0 40 20 80 60 100 Diameter

  13. RAIN CLOUD (CLW) ICE / SNOW GRAUPEL / HAIL Model Microphysics 1 Moment mass High Resolution Modelling Unobserved heavy precip on the lee side Kong and Yau 1 Moment Microphysics Pockets of liquid water are known to form in persistent terrain-induced updrafts and provide ideal regions for rapid riming growth of snow Almost no graupel formed (low riming rates)

  14. CLOUD (CLW) ICE (pristine crystal) SNOW (large crystals / aggregates) Model Microphysics 3 Moment mass High Resolution Modelling RAIN Windward and leeward precip in line with obs Milbrandt and Yau 3 Moment Microphysics HAIL (ice pellets) GRAUPEL Large graupel growth rates by riming

  15. High Resolution Modelling • Multimoment microphysics scheme reduces known accumulation and lee-side heavy precipitation problems with single moment schemes (e.g. IMPROVE case) • High resolution in steep terrain will challenge the numerics of GEM • High resolution verification data is hard to obtain but invaluable in scheme evaluation and further development

  16. Verification and Development • MAP and MAP D-PHASE produce unique verification datasets • D-PHASE will also be useful for model intercomparison at very high resolution • Quasi-operational status will yield statistically significant results on un-tuned cases • May be able to address the question of how much resolution is really needed? (> 3km)

  17. Conclusions • Addition of development cycle helps us to realize the full potential of MAP D-PHASE • Coupled or offline hydrology model development will be integral for Vancouver 2010 forecasting Development Cycle added to Canadian Operational Support

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